biome
group of ecosystems that have the same climate and dominant communities
ecosystem
collection of all the organisms that live in a particular place, together with their nonliving environment
community
assemblage of different populations that live togeter in a defined area
population
group of individuals of the same species that live in the same area
species
group of similar organisms that can breed and produce fertile offspring
biosphere
the part of Earth where life exists including land, water, and air or atmosphere
ecology
the scientific study of interactions among organism and between organisms and their environment
autotroph
organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds
chemosynthesis
process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates
carnivore
organism that obtains energy by eating animals
consumer
organism that relies on other organisms for its energy and food supplies
detritivore
organism that feeds of plant and animal remains and other dead matter
decomposer
organism that breaks down and obtains energy from dead organic matter
ecological pyramid
diagram that shows the relative ammounts of energy or matter within each trophic level in a food change or food web
biomass
total amount of living tissue within a given trophic level
food chain
series of steps in an ecosystem in which organisms transfer enrgy by eating and being eaten
food web
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
herbivore
organism that obtains energy by eating only plants
heterotroph
organism that obtains energy from the foods it consumes
omnivore
organism that obtains energy by eating both plants and animals
photosynthesis
process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates, such as sugars and starches
producer
organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds
trophic level
step in a food chain or food web
biogeochemical cycle
process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
denitrification
conversion of nitrates into nitrogen gas
evaporation
process by which water changes from a liquid into an atmospheric gas
algal bloom
an immediate increase in the ammount of algae and other producers that results from a large input of a limiting nutrient
limiting nurtient
single nurtient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem
nutrient
chemical substance that an organism requires to live
nitrogen fixation
process of converting nitrogen gas into ammonia
primary productivity
rate at which organic matter is created by producers in an ecosystem
transpiration
loss of water from a plant through its leaves